The subject of the present invention is an oxy-fuel torch and, more particularly, a system for controlling such a torch comprising at least three or four valves, and a single control for said valves collaborating with these and capable of adopting a first position in which said valves are at rest and a second stable position in which at least one of said valves is in the active position.
In the known way, oxy-fuel torches can be classified into three categories according to their use.
There are torches for cutting, also known as xe2x80x9cflame cuttersxe2x80x9d which, on the one hand, use a fuel gas such as C2H2 and, on the other hand, use oxygen as oxidizing agent. In these torches, it is necessary to supply gas to the pilot flame, when they have one, and to mix the gases to produce the heating flame and finally to provide a separate supply of oxygen to obtain the cutting jet.
In another category, in the case of heating or welding torches, also known as xe2x80x9cblow torchesxe2x80x9d or xe2x80x9cwelding torchesxe2x80x9d, respectively, all that is required is for the fuel, for example acetylene, to be mixed with oxygen to supply the main flame and supply the pilot flame.
However, in both instances, it is necessary, during the various stages of use (igniting the pilot, igniting the heating flame, possibly producing the cutting jet, extinguishing the main flame), to check the rate of delivery of the fuel and of the oxidizing agent so as to obtain the respective characteristics of heating, welding or cutting as desired, and to synchronize the successive phases of supplying the two gases, namely fuel and oxidizing agent.
In conventional torches, the control for opening and closing the supply of the two gases and for adjusting the delivery of these two gases is achieved using different controls.
In order to overcome these drawbacks, it has already been proposed for the controls for the supply of the two gases to be combined, for example as in the case of the torch described in document FR-A-2695458.
It has also been proposed for torches to be supplied that comprise a single device for controlling the gases and for ignition. A device such as this is described, for example, in document FR-A-2731266 or DE-A-2326125.
Other torches or control systems for torches are also described in the documents: U.S. Pat. Nos. 5,470,227, 5,792,281, EP-A-0895026 or FR-A-2770657.
However, in the case of the torches disclosed in these documents, while the technical arrangements described therein can sometimes lead to an improvement in the efficiency or operation of the torch in question, they do present certain drawbacks, and, in particular, in the case of some of them, that of encouraging incorrect use or inadvertent triggering.
Specifically, it can happen that the torch falls onto its control button or alternatively that, on a work site for example, the torch supply hoses become caught up in plant and that the torch, thus dragged along the ground, butts up against an obstacle, causing it to be unintentionally lit or causing the gases to be inadvertently switched on.
It can also happen that someone inexperienced attempts to extinguish a lit torch and incorrectly shuts the valves, allowing gas to leak or causing flashback.
Furthermore, it is also necessary to be able to adjust the delivery of fuel gas and the delivery of oxidizing gas delivered by the torch accurately.
In addition, it is also advantageous to be able to perform all or some of these adjustments during an initial phase and then to keep these adjustments for later use, that is to say after the torch has been put out a number of times. This is because such a possibility of preserving the settings makes it easier to carry out ignition to start with and avoids the phenomena of popping, the emission of smoke at the time of ignition and/or flaring.
With this as a starting point, one object of the present invention is therefore to provide an oxy-fuel torch which makes controlling the supply of gas to the torch simpler and safer and which allows the delivery settings for the oxidizing gas, such as the oxygen, and for the fuel gas, such as acetylene, to be memorized.
The solution of the invention is therefore a torch, particularly of the oxy-fuel type, comprising:
a body comprising a number of gas pipes for conveying at least two streams of gas between a number of inlets and a number of outlets;
at least two valves mounted in said body and capable of adopting a rest position in which the corresponding stream of gas is interrupted in at least one of said gas pipes and an active position in which the passage of the stream of gas is allowed through at least one of said gas pipes;
a single control for at least said two valves and mounted so that it can move on said body and able to be moved in a path so that it collaborates with at least said valves, said control being capable of adopting a first stable position in which said two valves are at rest and at least one second stable position in which at least one of said valves is in an active position;
controllable means of locking said control so as to secure, at rest, said control to said body, at least in said first position, and which can be actuated by hand to free said control from said body; and
at least one controllable delivery adjusting means mounted on said body for adjusting the delivery of at least one of said streams of gas, said adjusting means comprising a mobile control element.
Depending on the case, the torch of the invention may comprise one or more of the following features:
said control for said valves can be moved in translation in the direction of a longitudinal axis of said body;
it comprises an ignition system of the piezo-electric type;
it comprises two delivery adjusting means, each adjusting means being associated with one gas, particularly with oxygen, on the one hand, and with a fuel gas, such as acetylene, on the other hand;
the mobile control element is a rotary handwheel, preferably a rotary handwheel the position of which is indicative of the gas delivery adjusted;
each adjusting means comprises a tap comprising a tap body, a moving needle and a seat, and a handwheel being mounted so that it can rotate on said tap body so as to cause said needle to move;
at its active end, the needle comprises a delivery-adjusting axial portion and an annular sealing surface, said seat comprising an axial passage equipped with a zone with a progressive profile capable of collaborating with the adjusting portion of the needle so as to adjust the delivery of gas and an annular sealing rib surrounding said axial passage and capable of collaborating with said sealing surface when said needle is brought into its closed position;
each valve comprises a seat and a mobile shutter equipped with a control stem which has a control end, and said control comprises a slider external to the body of said torch and a cam secured to said slider, said cam being capable of collaborating or of not collaborating with the control end of the control stems of said valves according to the position of said slider;
said locking means comprises a push-button mounted so that it can move with respect to said slider and capable of adopting a rest position in which said slider is secured to the body of the torch and an active position in which said slider is free with respect to said body;
it comprises at least three valves, preferably at least four valves.
it comprises a first valve for controlling the fuel gas to deliver a pilot flame; a second and third valve for, respectively, controlling the main flame fuel gas and for controlling the main flame oxygen, the second valve also, on a branch, supplying the pilot flame ignition system; and a fourth valve for controlling the oxygen for the cutting jet. Said first, second and third valves are on/off valves and said fourth valve can be adjusted progressively. This version of torch is recommended for cutting a piece in which one of the gases is oxygen and the other gas is a fuel, said torch delivering a pilot flame, a main heating flame and a cutting jet;
it comprises means for defining a second stable position of said control in which position said first and fourth valves are in the rest position and the second and third valves are in the active position; it preferably also comprises means for defining a third stable position in which said second, third and fourth valves are in the active position and the first valve is in the rest position. Said third stable position of the slider corresponds to the second end of its path and said locking means adopts its rest position when said slider is in its first stable position at a first end of its path and when said slider is in its third stable position corresponding to the second end of its path;
as an alternative, it comprises a first valve for controlling the fuel for the pilot; a second valve for controlling the fuel for the heating flame; a third valve for controlling a system for igniting the pilot flame; and a fourth valve for controlling the oxygen for the heating flame; said valves preferably being of the on/off type. This version of the torch is preferred for heating a piece in which one of the gases is oxygen and the other gas is a fuel, said torch delivering a pilot flame and a main heating flame, said pilot flame being brought about by operating the ignition system. It comprises means for defining said second stable position of the control and, in this position, said second and fourth valves are in the active position and said first and third valves are at rest;
according to another alternative form, it comprises a first valve for supplying the main flame with oxygen; a second valve for supplying the main flame with fuel; and a third valve for supplying the pilot with fuel; said three valves preferably being of the on/off type. This version is preferred when two pieces are to be welded and one of the gases is oxygen and the other is a fuel gas, said torch delivering a pilot flame and a main welding flame.
More generally, the invention also relates to a torch comprising:
a body comprising a number of gas pipes;
at least two valves mounted in said body and capable of adopting a rest position in which the corresponding stream of gas is interrupted in at least one of said gas pipes and an active position in which the passage of the stream of gas is allowed through at least one of said gas pipes;
a single control for at least said two valves and mounted so that it can move on said body, collaborating with at least said valves and capable of adopting a first stable position in which said valves are at rest and at least one second stable position in which at least one of said valves is in the active position; and
at least one delivery adjusting means comprising a mobile control element and controllable so as to adjust the delivery of at least one of said streams of gas.
there are preferably two delivery adjusting means which are associated with each of the two gases consisting, respectively, of the oxidizing gas, such as oxygen, and the fuel gas, such as acetylene. Each adjusting means comprises a mobile control consisting of a rotary handwheel the angular position of which is indicative of the gas delivery in the gas pipe in question.
Using the torch of the invention, the implementation of the various phases of supply to the torch, whether it is a cutting, heating or welding torch, is carried out by actuating one single control and, in addition, this control is preferably equipped with a device for locking in at least the xe2x80x9coffxe2x80x9d position, thus avoiding accidental supply to the torch.
It will also be understood that by virtue of the presence of the one or more means for adjusting the delivery of at least one of the gases distinct from the torch gas supply valves, the various settings can be memorized and/or preserved even after the torch has been extinguished.
Furthermore, this separation between the controls by valves which may be of the on/off type, and the delivery adjusting members makes it possible to make the delivery adjusting means far more effective and accurate.
In the context of the present invention, the words xe2x80x9cgas pipexe2x80x9d are used to denote any duct, line or passage or any other gas circuit formed in the body of the torch and allowing the various streams of gas to be transported within said torch body.